Insulating panels

ABSTRACT

The present invention relates to improvements in or relating to insulating panels. In particular, the present invention relates to an insulating panel comprising heat-exchanging and ventilation means for use in buildings. We describe an insulating and ventilating system for a roof or a wall comprising such an insulating panel having at least one internal longitudinal flue divided by a heat-transfer element; and an insulating panel and its use in a roof structure or wall cavity.

The present invention relates to improvements in or relating to insulating panels. In particular, the present invention relates to an insulating panel comprising heat-exchanging and ventilation means for use in buildings.

With ever increasing energy efficiency standards, a sufficient but controlled supply of air for ventilation is a requirement of modern buildings, in terms of the health of the occupants, energy use and efficiency levels. Insulation in the form of glass-fibre wool and expanded plastics foam, such as polystyrene, are routinely used within the building industry to increase thermal efficiency and reduce energy consumption within buildings.

JP 2006307615 describes a frameless heat-insulated double ventilation layer panel for installation between the roof-trusses of a building. The layered panel consists of a sheathing plate and an insulating panel in which the insulating panel is mounted on spacer members, attached to its first face, to the rear surface of the sheathing plate. The spacer members provide a first ventilation layer interposed between the sheathing plate and insulation material. Further spacer members are attached to a second face of the insulating panel and, in an installed configuration in which the insulating panel is fitted between adjacent roof-trusses, the spacer members provide a second ventilation layer interposed between the roof structure and the insulating panel.

The insulation material is utilised to separate the two ventilation layers (and their corresponding air-flows), with the insulation material interposed between the ventilation layers to reduce heat transfer between each ventilation layer and control interstitial condensation rather than to provide fresh air for the occupants.

JP 2007024407 describes a ventilation system comprising a ventilating device linked by a network of ducts to a series of ceiling-mounted air-intake ports and air-output ports, in which the air-intake ports remove stale air from a room and expel it, through the ventilation device to outside the building, and the air-output ports deliver fresh air from outside of the building into a room, via the ventilation devices. The ventilation device includes suction devices for sucking and delivering fresh air into the building, and for sucking and expelling stale air from the building.

Whilst the insulating panel of JP 2006307615 helps to prevent heat loss from a building in terms of any accumulated heat within a loft space, it is thermally inefficient due to the fact that, during the process of ventilation, stale warm air from within the building is simultaneously expelled from the building whilst fresh colder air is drawn into the building. This has the overall effect of reducing the temperature within the building and consequently, to compensate for the loss of heat, the building's heating system will need to be used. This principle also applies to the ventilation system of JP 2007024407, and represents a significant problem in terms of cost to the homeowner and environment. Additionally, such systems tend to result in a higher level of stale moisture-laden air which is undesirable to both occupants and the fabric of the building.

Accordingly, it is desirable to provide an insulating panel which does not suffer from at least some of these problems, and which provides a more thermally efficient means for insulating a building.

The present invention provides an improved insulating panel which additionally comprises thermally efficient means for ventilating a building.

In a first aspect of the present invention, there is provided an insulating panel comprising a panel comprising an insulation material and having at least one internal longitudinal flue divided by a heat-transfer element.

Preferably, the heat-transfer element longitudinally divides the flue along a principle plane which intersects adjacent truss beams of a roof between which the insulating panel is fixable, in use.

Optionally, the insulating panel comprises a plurality of internal flues. Suitably, the insulating panel comprises two internal flues.

Preferably, the heat-transfer element comprises a reinforcement webbing.

Preferably, the at least one internal flue traverses opposed longitudinal faces of the insulating panel. More preferably, the at least one internal flue traverses opposed longitudinal faces of the insulating panel across substantially the whole longitudinal length of the insulating panel.

Preferably, the internal flue further comprises a filter to prevent the ingression of, for example, pollen, dust, insects, birds or small mammals.

Suitably, the insulation material is an expanded plastics foam. Preferably, the insulation material is polystyrene, polyurethane or polyisocyanurate.

Suitably, the insulating panels are adapted for insertion between adjacent trusses of a roof, or between stud-work or within a cavity of an external wall structure. Preferably, each insulating panel further comprise securing means which, in use, permit the insulating panels to be secured to adjacently located roof trusses or studs. Suitably, the securing means are laterally projecting flanges and fixing means, suitably in the form of screws or nails. Optionally, the insulating panels are interlockable with adjacently located insulating panels.

Alternatively, the insulating panel securing means is an expandable foam precursor which is expandable to fill any voids which may exist between the panel and its corresponding roof trusses. Suitably, the expandable foam precursor is a sprayable gel or foam. Alternatively, the securing means is an adhesive tape comprising conventional adhesive means on a first side, for securing the tape to an insulating panel, and an expandable foam precursor covered by the tear-off strip on a second side, wherein the expandable foam precursor may be activated by removal of the tear-off strip.

Suitably, the insulating panels are interlockable with vertically adjacent panels. Alternatively, the panels are abuttable with adjacent panels and any voids between panels may, optionally, be filled with an expandable foam.

According to a second aspect, the present invention provides an insulating and ventilating system for a roof or a wall, the system comprising:

-   -   i) a plurality of insulating panels as defined above;     -   ii) a plurality of ventilation exhaust/intake ports; and     -   iii) ducting interposed between the at least one internal flue         of each respective insulating panel, and the plurality of         ventilation exhaust/intake ports.

Optionally, the system further comprises a manifold. Preferably, ducting is interposed between the manifold and the at least one internal flue of each respective insulating panel, and the manifold and the plurality of ventilation exhaust/intake ports. Suitably, the manifold comprises a system control means for isolating a flow of air through ducting connecting particular ventilation exhaust/intake ports from a specific location within the building. This arrangement facilitates modification of the system to provide a plurality of multiple ‘closed ventilation systems’ to prevent noise transfer, for example that associated with a fan operating in bathroom or kitchen, through the ducting to a quiet room such as a bedroom.

Suitably, the manifold comprises one or more manifold-filters. Preferably, the manifold-filters are removable. Preferably, the manifold-filters remove particulates, such as dust and pollen, from air which enters the system from outside of the building.

Suitably, the ventilation intake ports further comprise a room-filter. Preferably, the room-filters are removable.

Optionally, the system further comprises at least one fan to drive the exchange of stale air, from within a building fitted with the system, with fresher air from outside of the building. Suitably, the at least one fan is controllable by a switching means. Suitably, the switching means is activated by simple mechanical means such as a dedicated switch or a light switch. Alternatively, the switching means is activated by one or more sensors; for example those which are sensitive to levels of carbon dioxide, oxygen, humidity or occupancy within a particular room. Suitably, the switching means further comprises a timer such that, in use, the at least one fan is operational for a pre-determined time after the switching means has been deactivated.

Suitably, the system additionally comprises a plurality of flueless insulating panels. Preferably, in use, the flueless insulating panels are fitted in regions where it is impractical to fit insulating panels according to the first aspect of the invention.

In a third aspect there is provided the use of an insulating panel as defined above, in a roof structure or wall cavity.

The above and other aspects of the invention will now be illustrated in further detail, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 is a schematic sectional view of a roof incorporating an insulating panel according to the first aspect of the invention;

FIG. 2A is a schematic sectional view along the line A-A of FIG. 1;

FIGS. 2B-F are schematic sectional views along the line A-A of alternative flue/heat-transfer element arrangement; and

FIG. 3 is a schematic sectional view of an insulating and ventilating system according to the second aspect of the invention.

Referring to FIGS. 1 and 3, there is shown an insulating and ventilating system 10 for a roof or a wall in which the system includes a plurality of insulating panels 11 formed from a substantially rigid insulating material of, for example, polystyrene, polyurethane or polyisocyanurate, and having an internal flue 12. The flue 12 is connected at an uppermost end of the panel 11 through ducting 13 to a manifold (not shown) and is open at a lowermost end to an external aspect of the roof structure. In preferred systems, the lowermost end of the flue is in fluid communication with the eaves 50 and guttering 51, so that any condensation which develops in the flue can drain to the guttering and fresh air can be drawn into the system from the eaves.

Additionally, the lowermost end of each flue is provided with a filter (not shown) suitable to prevent, for example, dust, pollen, insects, birds and small mammals from entering the system. In systems in which the insulation panel flues are linked via ducts to the eaves and guttering, the ducting will be provided with such filters.

The flue comprises an air-intake flue 12 a, which permits an air-flow from the exterior to the interior of a building in which the system is installed, and air-exhaust flue 12 b, which permits an air-flow from the interior to the exterior of the building. The flue is divided into the air-intake flue 12 a and air-exhaust flue 12 b by a heat-transfer membrane 14, which provides a substantially air-tight seal between the air-intake and air-exhaust flues 12 a and 12 b, and, in use, permits the transfer of heat energy between air-flows within the respective flues. The air-intake flue 12 a will typically source at the building eaves 50, whereas the air-exhaust flue 12 b will typically exhaust to the roof guttering 51.

Independent ducts 13 a, 13 b are connected to each respective flue 12 a, 12 b to isolate the respective air-flow through flues 12 a and 12 b. In turn, the ducting 13 a, 13 b is connected to a manifold (not shown), which is subsequently connected to one or more ventilation intake/exhaust ports within a room. Alternatively, the ducts 13 a, 13 b are connected directly to one or more ventilation intake/exhaust ports within a room, without the need for a manifold.

In preferred embodiments, the system includes a manifold, the addition of which facilitates the linkage of a number of insulation panels for the common ventilation of one or more rooms. Additionally, in preferred systems the manifold also includes a system control means for isolating a flow of air through ducting connecting particular exhaust/intake ports from a specific location within the building. Such a controlled system allows respective air-flows through the manifold to be adjusted, and a number of insulation panels can be used in the ventilation of a single room, for example, where high levels of ventilation are required such as in a bathroom or kitchen. In the controlled system, the manifold is adjustable to allow the ventilation pathways between specific insulating panels and ventilation intake/exhaust ports to be actively isolated from the general system to thereby create a number of separate ‘ventilation systems’ within the main system. This flexibility means that the arrangement can be used to help prevent noise transfer through the system, so that, for example, noise associated with a fan operating in a bathroom or kitchen is not transferred through the ducting to a more quiet room, such as a bedroom. Additionally, it also allows the air-flow to be modified to adjust the exchange rate of air within a particular room.

Further, in preferred embodiments the manifold includes one or more manifold-filters for removing dust and pollen from air which enters the system from outside of the building. In particularly preferred embodiments, the manifold-filters are removable. The filters also act to prevent insects, birds and small mammals from entering the system.

In preferred embodiments (not shown), a reinforcement webbing supports the heat-transfer membrane to reduce the effect of air pressure changes and mechanical stress upon the membrane. The provision of a reinforcement webbing is advantageous since the thermal efficiency of the panel directly correlates with the thickness of the heat-transfer membrane and it is desirable to use very thin heat-transfer membranes in order to provide maximum thermal efficiency levels. Accordingly, insulating panels which include reinforcement webbings permit the use of very thin and thermally efficient heat-transfer membranes, and are advantageous to prolong the life expectancy of such membranes in order to reduce the likelihood of a failure which could result in a short circuit of the panel between air-flows.

The specific design of the internal flue system of each insulating panel according to the invention provide a relatively large surface area available for heat transfer and exchange, and the positioning of the heat-transfer membrane, so that the air-flow temperatures coincide with the temperature profile across the insulating panel, ensures a high thermal efficiency. Examples of a number of flue designs are shown sectionally in FIGS. 2B-2D.

In alternative embodiments, the insulating panels include a plurality of flues, which provide an increase in the ratio of the surface area of the heat-transfer membrane to volume of the respective flues and, accordingly, an increase in the rate of thermal transfer between two opposing air-flows divided by the heat-transfer membrane. An example is shown in FIG. 2A. As a result, a reduction in heat-loss from a building due to ventilation is observed.

In use of the described insulating and ventilating system of the invention, a number of insulating panels are interposed between the interior and exterior structure of a building in order to help maintain a stable temperature within the building. In particular, and as illustrated schematically in FIG. 3, the internal flue or flues of each insulating panel are preferably arranged so that the temperature of the respective air-flows within each flue corresponds with the temperature profile across the insulating panel. That is to say, where an air-flow through the flue has a temperature which is close to that of the temperature inside the building, the degree of insulation between the flue (and thus the air-flow) and the inside of the building is less than the corresponding degree of insulation between the flue and the outside of the building. According to this arrangement, the degree of insulation on the side of the insulating panel exposed to the interior of the building decreases from B to C (see FIG. 3) along the length of the panel. Conversely, the degree of insulation on the side of the insulating panel exposed to the exterior of the building increases from B to C along the length of the panel, as the temperature of the air-flow tends towards the external air temperature. Accordingly, the flue takes a generally diagonal path through the insulating panel, as depicted in FIGS. 1 and 3.

As illustrated in FIGS. 1 and 3, the air-intake channel 12 a within the at least one flue is positioned relative to the interior of the building, and in this arrangement a large degree of the heat exiting the building through the air-exhaust channel 12 b is recoverable across the heat-transfer membrane 14 when temperatures outside of the building are lower than those within the building. Conversely, when temperatures outside of the building are higher than those within the building, and the building is being cooled by an air-conditioning device, the ventilation system will help reduce the cooling load, used for the fresh air intake, by transferring heat to the exhaust air-flow. Under such circumstances the system would need to be mechanically driven, since it would oppose the stack effect (see below).

There is also a tendency for condensation to form as a result of the reduction in temperature of the exhaust air-flow, particularly with air extracted from kitchen and bathroom areas, and this releases additional latent heat to the incoming air, via the separating membrane.

In preferred embodiments, the ventilation intake/exhaust ports include one or more removable filters. In particular, ventilation intake/exhaust ports located in a kitchen, and to a lesser extent in a bathroom, are provided with filters to help to prevent vaporised cooking oils and greases from entering and being deposited within the system ducts and/or flues.

An insulating and ventilating system according to the present invention has significant advantages over existing systems by reducing energy consumption.

A conventional way to ventilate a building is to make use of what is known as the ‘stack effect’. This effect exploits the difference in temperature and density of the air inside a building with that outside of the building. For example, the effect will result in a natural flow of air between openings, such as a window, door, crack or ventilation gap, in upper and lower parts of a building. If the air within the building is warmer than the external air temperature, this warmer air will flow towards the upper opening. As a result of a reduction in pressure caused by the movement of warm air, cooler air will be sucked in from outside of the building to replace the volume of warm air. In instances where the air inside the building is cooler than that outside, the cooler air will flow out of the building from the low opening, and will be replaced with warmer air from outside.

Due to the natural incline of a sloping roof structure, the insulating panels are also inclined which facilitates a natural circulation of air through the system as a result of the stack effect. This reduces the need for forced ventilation by fans. However, where there are higher levels of moisture and warm air, such as in a bathroom or kitchen, it is desirable to use fans to help force the ventilation.

In a typical roof construction, due to the relatively large number of trusses within each roof structure, it is not necessary for all of the insulating panels to provide a heat exchange function since not all of the insulating panels are likely to be required for ventilation purposes. In such systems, insulating panels which do not include an internal flue are used in conjunction with the system described above, to help reduce costs. The use of such flueless panels would be appropriate for installation in the roof structure above a dormer window, for example.

The provision of flueless insulating panels also means that the insulating panels comprising a flue can be supplied in standard lengths and do not have to be supplied in bespoke roof lengths. Additionally, the flueless panels could readily be cut to suit the length and pitch of the particular roofs. Due to the lower relative costs of manufacture, flueless panels can be made in a range of lengths and widths to accommodate all roof sizes, to provide insulation where ventilation is not required. For example, the trusses on one side of a roof can be fitted with flued insulating panels and where such panels provided sufficient ventilation capacity for the building, flueless panels can be used on the opposite roof side.

The described system offers significant advantages in terms of improvement of air quality and also health over conventional air conditioning systems in which most of the air passing through the system is recycled with perhaps only around 20% of the air being exchanged for fresh air in order to reduce the cooling load. A system according to the present invention permits the exchange of up to 100% of the air within an air-conditioned building with a minimal loss of heat energy due to the exchange of air. The system also leads to a reduction in the build-up of condensation within a building.

For ease of fitting, the insulating panels are supplied in a range of standard widths and lengths to fit between a pair of adjacent roof trusses, FIG. 2A, 52. The panels are suitably fitted during construction of the roof structure, and prior to the laying of any roof tiles or other surfacing, although they can equally be fitted retrospectively once the roof structure has been completed. A benefit of fitting during the construction of the roof is that the insulating panels help to stabilise the roof structure. In addition, the panels can be fitted relatively quickly and also used to seal the building to the elements. Ducting is subsequently fitted to link the flue to one or more manifolds, and to the exhaust/intake ports of the system.

In an insulating and ventilating system as described, including fans, controls and ductwork, the panels provide a whole house ventilation system with means for heat recovery.

Although the panels will be used primarily in a heating mode they would also be effective in conjunction with forced ventilation in a cooling mode.

An insulating and ventilating system according to the invention is also suitable for incorporation into an external wall. 

1. An insulating panel comprising a panel comprising an insulation material and having at least one internal longitudinal flue divided by a heat-transfer element.
 2. An insulating panel as claimed in claim 1, wherein the heat-transfer element longitudinally divides the flue along a principle plane which intersects adjacent truss beams of a roof between which the insulating panel is fixable, in use.
 3. An insulating panel as claimed in claim 1 or claim 2, wherein the panel comprises a plurality of internal flues.
 4. An insulating panel as claimed in claim 3, wherein the panel comprises two internal flues.
 5. An insulating panel as claimed in any one of claims 1 to 4, wherein the heat-transfer element comprises a reinforcement webbing.
 6. An insulating panel as claimed in any one of claims 1 to 5, wherein the at least one internal flue traverses opposed longitudinal faces of the insulating panel.
 7. An insulating panel as claimed in any one of claims 1 to 5, wherein the at least one internal flue traverses opposed longitudinal faces of the insulating panel across substantially the whole longitudinal length of the insulating panel.
 8. An insulating panel as claimed in any one of the preceding claims, wherein the internal flue further comprises a filter to prevent the ingression of insects, birds or small mammals, or particulates such as pollen and dust.
 9. An insulating panel as claimed in any one of the preceding claims, wherein the insulation material is an expanded plastics foam.
 10. An insulating panel as claimed in claim 9, wherein the insulation material is polystyrene, polyurethane or polyisocyanurate.
 11. An insulating panel as claimed in any one of the preceding claims, wherein the insulating panels are adapted for insertion between adjacent trusses of a roof, or between stud-work or a cavity of an external wall structure.
 12. An insulating panel as claimed in any one of the preceding claims, wherein each insulating panel further comprise securing means which, in use, permit the insulating panels to be secured to adjacently located roof trusses or studs.
 13. An insulating panel as claimed in claim 12, wherein the securing means are laterally projecting flanges and fixing means, suitably in the form of screws or nails.
 14. An insulating panel as claimed in claim 12 or claim 13, wherein the insulating panels are interlockable with adjacently located insulating panels.
 15. An insulating panel as claimed in any one of claims 12 to 14, wherein the insulating panel securing means is an expandable foam precursor which is expandable to fill any voids which may exist between the panel and its corresponding roof trusses.
 16. An insulating panel as claimed in claim 15, wherein the expandable foam precursor is a sprayable gel or foam.
 17. An insulating panel as claimed in any one of claims 12 to 14, wherein the securing means is an adhesive tape comprising conventional adhesive means on a first side, for securing the tape to an insulating panel, and an expandable foam precursor covered by the tear-off strip on a second side, wherein the expandable foam precursor may be activated by removal of the tear-off strip.
 18. An insulating panel as claimed in any one of claims 12 to 17, wherein the insulating panels are interlockable with vertically adjacent panels.
 19. An insulating panel as claimed in any one of claims 12 to 17, wherein the panels are abuttable with adjacent panels and any voids between panels may, optionally, be filled with an expandable foam.
 20. An insulating and ventilating system for a roof or a wall, the system comprising: i) a plurality of insulating panels as claimed in any one of claims 1 to 19; ii) a plurality of ventilation exhaust/intake ports; and iii) ducting interposed between the at least one internal flue of each respective insulating panel, and the plurality of ventilation exhaust/intake ports.
 21. An insulating and ventilating system as claimed in claim 20, wherein the system further comprises a manifold.
 22. An insulating and ventilating system as claimed in claim 21, wherein the system further comprises ducting interposed between the manifold and the at least one internal flue of each respective insulating panel, and the manifold and the plurality of ventilation exhaust/intake ports.
 23. An insulating and ventilating system as claimed in claim 21 or claim 22, wherein the manifold comprises a system control means for isolating a flow of air through ducting connecting particular ventilation exhaust/intake ports from a specific location within the building.
 24. An insulating and ventilating system as claimed in any one of claims 21 to 22, wherein the manifold comprises one or more manifold-filters.
 25. An insulating and ventilating system as claimed in claim 24, wherein the manifold-filters are removable.
 26. An insulating and ventilating system as claimed in claim 25, wherein the manifold-filters remove dust and pollen from air which enters the system from outside of the building.
 27. An insulating and ventilating system as claimed in any one of claims 20 to 26, wherein the ventilation intake ports further comprise a room-filter.
 28. An insulating and ventilating system as claimed in claim 27, wherein the room-filters are removable.
 29. An insulating and ventilating system as claimed in any one of claims 20 to 28, wherein the system further comprises at least one fan to drive the exchange of stale air, from within a building fitted with the system, with fresher air from outside of the building.
 30. An insulating and ventilating system as claimed in claim 29, wherein the at least one fan is controllable by a switching means.
 31. An insulating and ventilating system as claimed in claim 30, wherein the switching means is activated by simple mechanical means such as a dedicated switch or a light switch.
 32. An insulating and ventilating system as claimed in claim 30 or claim 31, wherein the switching means is activated by one or more sensors; for example those which are sensitive to levels of carbon dioxide, oxygen, humidity or occupancy within a particular room.
 33. An insulating and ventilating system as claimed in any one of claims 30 to 32, wherein the switching means further comprises a timer such that, in use, the at least one fan is operational for a pre-determined time after the switching means has been deactivated.
 34. An insulating and ventilating system as claimed in any one of claims 20 to 33, wherein the system additionally comprises a plurality of flueless insulating panels.
 35. An insulating and ventilating system as claimed in claim 34, wherein in use, the flueless insulating panels are fitted in regions where it is impractical to fit insulating panels according to the first aspect of the invention.
 36. Use of an insulating panel as claimed in any one of claims 1 to 19, in a roof structure or wall cavity.
 37. An insulating panel substantially as herein described, with reference to the accompanying drawings.
 38. An insulating and ventilating system substantially as herein described, with reference to the accompanying drawings. 